I cannot comment much re tires, but in terms of doping the period
before W.W.II was pretty much the wild west. Following W.W.II , and the
development of amphetamines to keep pilots and soldiers alert, there
really was nothing of proven effectiveness. From the 1890's on riders
tried just about anything and everything to improve their performance.
Researchers in the field cite ether, brandy, crushed bull gonads, sperm
from animals (hope I don't get bounced for this), coffee. John
Hoberman, from the University of Texas, observed that athletes of this
day were essentially guinea pigs for medical science. They would try
anything just to see if it worked or not. And, unlike the post Tommy
Simpson era, doping was not illegal and often it was not even considered
a problem. It was just taken for granted as part of sport.
Edward Albert
Chappaqua, NY